1. The Field of the Invention
The present invention relates to a tube launched rocket system which includes a plurality of small propellant charges located within the tube which propel the rocket by thrusting gases into a travelling propulsion chamber. More particularly, the present invention relates to a tube launched rocket system which uses relatively non-toxic propellant and produces manageable levels of noise.
2. Technical Background
One staple of modern military operations is the tube launched weapon system such as conventional anti-aircraft and anti-tank weaponry. These systems generally involve the firing of a projectile which utilizes a rocket motor for propulsion. The rocket propelled projectile is launched from an open tube. As a result, these devices are classified as open breech devices, as opposed to rifles, howitzers and the like which launch a projectile from a tube having one closed end.
Tube launched weapon systems are very important in modern military operations. A foot soldier using these systems can deliver much larger quantities of explosive force than was possible using conventional closed breech infantry weapons. For example, anti-tank and anti-aircraft missiles can be launched using a tube system supported by a man's shoulder. Because the aft end of the tube is open, recoil from the rocket motor is manageable, and there is no need to construct massive recoil absorption systems such as those found on a howitzer.
Tube launched weapon systems face several significant design problems. For example, in previously disclosed systems the projectile launched by the system includes a rocket motor for propulsion. It is critical that the motor completely burn out before it leaves the tube; if the rocket motor is still burning when it exits the tube, the hot exhaust may severely injure the system's user. Thus, the propellant in the rocket motor must burn extremely rapidly but still provide maximal forward thrust.
In addition, the propellant must be designed to perform properly under a wide range of ambient conditions. For example, it is preferable that the propellant function equally well at sea level and at high altitudes, in extreme heat and extreme cold, in jungle humidity and in arid desert air. It will be appreciated, however, that designing the propellant to burn out before exit under such extreme conditions results in a rocket motor that provides less than optimal performance under most circumstances.
Another serious concern is the noise produced by operation of the system. Since the propellant must be consumed while the projectile is in the launch tube, it must burn with almost explosive force. In addition, many conventional devices of this type include a plug in the throat of the rocket motor. The ignition of the rocket motor must produce enough force to immediately dislodge the plug. The required pressure is generally in the range of 50 to 150 psi. In typical devices of this type the rise time, or time of pressurization, is in the range of about 5 to 10 milliseconds. Within 50 milliseconds, the projectile has exited the tube. Creating the require pressure within the permitted time results in a significant pressure wave following burn out of the rocket motor.
Ignition and launch of the rocket motor therefore produce a very large sound wave. Indeed, the sound wave is large enough that it presents a significant safety concern. The sound wave itself has the potential of causing injury or death to the user. Accordingly, it is now conventional for the user to wear ear plugs, ear muffs, and a helmet.
The pressure and sound waves caused by the launch of tube launched rocket motors are such that it is not possible to safely operate the device within a building. Such operation may damage the building and endanger the occupants of the building. This limitation is significant in that there are often situations where use of such devices within a building would be desirable.
Another problem encountered in the use of this type of device is the relative toxicity of the propellant. Conventional propellants used in devices of this type contain significant levels of lead and/or copper. Therefore, repeated use of the device by a single soldier, as during practice exercises, poses a health risk.
Thus, it would be an advancement in the art to provide a tube launched weapon system capable of imparting adequate forward thrust to a projectile through the use of relatively non-toxic propellant.
It would also be an advancement in the art to provide a high-performance tube launched weapon system that produces manageable levels of noise.
It would be a further advancement in the art to provide a tube launched weapon system in which the requirement of protecting users from rocket motor exhaust burns was not a significant constraint on propellant composition.
It would also be an advancement in the art to provide a tube launched weapon system configured to facilitate user adjustments in the amount of propellant employed.
Such an apparatus is disclosed and claimed herein.